Abstract. Fungal contaminants are significant public health concerns, yet critical questions remain regarding fungal exposures and their respiratory health impacts following a major flooding event. Clarifying these associations is particularly important for public health given increasing flood risks in many regions of the United States. Previous epidemiological research on flooding, fungi, and human health impacts has been equivocal, which may in part result from key limitations in the methods used in previous research to measure fungal communities. Traditional culture and microscopy-based methods can lead to misclassification of the amounts and types of fungi in homes following floods. Fungal communities are better characterized using the state-of- the-art technique of high-throughput DNA sequencing. Further, fungi release volatile organic compounds (VOCs), which can also be harmful to respiratory health. However, these compounds have not been extensively studied in previous epidemiological studies of flood-related fungal exposures. Here we propose to sample 50 flood-damaged and 50 unharmed homes in Houston to ascertain fungal amounts and types following the catastrophic flooding impacts of Hurricane Harvey, using state-of-the-art fungal measurement techniques including measurements of fungal VOCs. We further propose to investigate how these fungal measurements are associated with asthma exacerbations among occupants, measured using a Bluetooth- enabled rescue inhaler. This project therefore aims to: (1) improve characterization of fungal exposures (including exposures to taxa with allergenic capacity and fungal diversity) in flood damaged homes using DNA sequencing-based methods; (2) ascertain the association between types of fungi and specific VOCs present in flood-damaged homes; and (3) measure associations between these fungal measurements and sub-acute asthma exacerbations. As an exploratory subaim, we also propose to use geospatial analyses to link these fungal measurements with neighborhood geospatial flood risk-related data from public data sources that are available before or rapidly after floods, as a first step in developing rapid-response risk mapping tools for flood- related fungal exposures. Due to the time since Harvey's landfall, we have a limited opportunity to characterize the airborne fungi and associated short-term health effects among occupants, especially those with asthma. However, if this innovative research can be initiated quickly, it will provide greater insight into the effects of flooding events on exposures to fungal contaminants and attendant short-term respiratory health consequences.